Adding video to video module breaks page—with a weird twist

I’m running into a weird issue with a landing page that I’m building with Beaver Builder (technically it’s the Woo360 white labeled version).

When I add a video to the page with the video module, and set it to load a video from the media library, the page breaks. Meaning that all of the content from the video player on won’t load. When I inspect the rendered HTML it looks like the code is there, but it’s commented out. Definitely odd.

But where things get really weird is, if I add any arbitrary query string to the page URL, it works fine.

So is broken, but works fine.

I’ve tried deleting the video module and recreating it, as well as toggling on and off all of the different video settings to see if one of them was triggering a bug.

I was able to reproduce it on a simplified page that only contains the video module plus a header that should render after the video player.

When I inspect the HTML I’m seeing the following:

<!--[if lt IE 9]><script>document.createElement('video');</script>&lt;![endif]--&gt;
<video class="wp-video-shortcode" id="video-31385-1" width="640" height="360" 
preload="metadata" controls="controls">
<source type="video/mp4" src="">
</source><a href=""></a></video></div></div>

Note the --&gt: at the end of the first line. Almost seems like someone copy/pasted some code that was improperly encoded.

Anyone ever see anything like this before?

Any troubleshooting suggestions?